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Icompatible chemicals

Chemicals that react when stored together.

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Reactive and Incompatible Chemicals ¹

This list includes only the most important examples. These chemicals react violently when they come into contact with each other and must not be stored together.Mixing incompatible chemicals in a waste container can form an explosive mixture, for example, nitric acid and ethanol. If a bottle broke in a waste storage area where incompatibles were present, the results could be disastrous. Remember: incompatible bottles of wastes should be stored separately. The objective is to avoid accidents in the laboratory. See table below for the possible reactions that may occur due to impropper storage of chemicals.

See also: immiscible solvents and solvent drying


Incompatible with

Acetic acid Chromium oxide, nitric acid, perchloric acid, peroxides, permanganates, alcohol, ethylene glycol
Acetic anhydride Hydroxyl-containing compounds e.g. ethylene glycol, perchloric acid
Acetone Concentrated nitric acid and sulphuric acid mixtures, hydrogen peroxide
Acetylene Chlorine, bromine, fluorine, copper, silver, mercury
Activated carbon Calcium hypochlorite, oxidizing agents
Alkali metals Water, carbon tetrachloride and other halogenated alkanes, carbon dioxide, halogens. (Do not use water or foam extinguishers for fires involving these metals Use the appropriate class D extinguisher.
Aluminium All oxidizing agents, acids, alkalis, halogenated hydrocarbons, peroxides
Aluminium alkyls water
Ammonia, liquid or gas Mercury (e.g. in pressure gauges), chlorine, calcium hypochlorite, iodine, bromine, hydrogen fluoride
Ammonium nitrate Acids, powdered metals, flammable liquids, chlorates, nitrates, sulfur, fine-particulate organic or combustible materials
Aniline Nitric acid, hydrogen peroxide
Arsenic materials Any reducing agent
Azides Acids
Bromine see chlorine
Calcium oxide Water
Carbon activated Calcium hypochlorite, other oxidants
Chlorine Ammonia, acetylene, butadiene, butane, methane, propane, hydrogen, petroleum benzine, benzene, powdered metals
Chlorates Ammonium salts, acids, powdered metals, sulfur, fine-particulate organic or combustible substances
Chromium (V1) oxide, chromic acid Acetic acid, naphthalene, camphor, glycerol, petroleum benzine, alcohols, flammable liquids
Copper Acetylene, hydrogen peroxide
Cumene hydroperoxide Acids, both organic and inorganic
Cyanides Acids
Flammable liquids Ammonium nitrate, chromium (VI) oxide, hydrogen peroxide, nitric acid, sodium peroxide, halogens, chromic acid.
Fluorine Extremely aggressive; store separately! Isolate from everything!
Hydrazine Hydrogen peroxide, nitric acid, any other oxidant
butane, propane, benzene etc.
Fluorine, chlorine, bromine, chromium (VI) oxide, sodium peroxide
Hydrogen fluoride Ammonia (laboratory gas or solutions)
Hydrogen peroxide Copper, chromium, iron, metals and metal salts, alcohols, acetone, organic substances, aniline, nitromethane, combustible substances (solid or liquid)
Hydrogen sulphide Fuming nitric acid, oxidizing gases
Hypochlorites Acids, activated carbon
Iodine Acetylene, ammonia (laboratory gas or solutions)
Mercury Acetylene, ammonia
Nitrates and nitrites Acids
Nitric acid Acetic acid, aniline, chromium (VI) oxide, prussic acid, hydrogen sulfide, flammable liquids and gases
Nitroparaffins Inorganic bases, amines
Oxalic acid Silver, mercury, mercury salts
Perchloric acid Acetic anhydride, bismuth and its alloys, alcohols, paper, wood, grease. oil, (all organics)
Peroxides, organic Acids (organic and inorganic), avoid friction, store cold.
Phosphorus Sulfur, compounds containing oxygen, e.g. chlorates, air, oxygen
Phosphorus pentoxide Alcohols, strong bases, water
Potassium Carbon tetrachloride,carbon dioxide, water
Potassium chlorate see chlorate
Potassium perchlorate see chlorate
Potassium permanganate Glycerol, ethylene glycol, benzaldehyde, sulfuric acid
Silver Acetylene, oxalic acid tartaric acid, ammonium compounds
Sodium see alkali metals
Sodium peroxide Methanol, ethanol, glacial acetic acid, acetic anhydride, benzaldehyde, carbon disulfide, glycerol, ethylene glycol, ethyl acetate, methyl acetate, furfural
Sulphides Acids
Sulphuric acid Potassium chlorate, potassium perchlorate, potassium permanganate
sulphur Metals, all oxidizing agents
Zinc All oxidizing agents, acids, alkalis, halogenated hydrocarbons, peroxides

Reactions of incompatible chemicals ²

Chemicals Stored Together Possible Reaction

1. Acetic acid & Acetaldehyde

Small amounts of acetic acid will cause the acetaldehyde to polymerize, releasing heat.

2. Acetic anhydride & Acetaldehyde

Reaction can be violently explosive

3. Aluminum metal & ammonium nitrate

A potential explosive.

4. Aluminum & bromine vapor

Aluminum foil reacts with bromine vapor at room temperature and incandesces.

5. Ammonia vapor & bromine vapor

Unstable nitrogen tribromide is formed, explosion may result.

6. Ammonium nitrate & acetic acid

A mixture may result in ignition, especially if acetic acid is concentrated.

7. Cupric sulfide & cadmium chlorate

Will explode on contact.

8. Hydrogen peroxide & ferrous sulfide

Forms a vigorous, highly exothermic reaction.

9. Hydrogen peroxide & lead II or IV oxide

Violent, possibly explosive reaction.

10. Lead perchlorate & methyl alcohol

Forms an explosive mixture if agitated.

11. Lead sulfide & hydrogen peroxide

Vigorous, potentially explosive reaction.

12. Mercury II nitrate & methanol

May form mercury fulminate - an explosive.

13. Nitric acid & phosphorus

Phosphorus burns spontaneously in the presence of nitric acid.

14. Potassium cyanide & potassium peroxide

A potentially-explosive mixture if heated.

15. Sodium nitrate & sodium thiosulfate

A mixture of the dry materials can result in an explosion.

References :
1. Merck chemical company.
2. Chemical Safety Office, Risk Management Department, University of Vermont.
3. Hazards in the Chemical Laboratory, 4th. edition. 1986. Bretherick.

Signature: Dhanlal De Lloyd, Chem. Dept, The University of The West Indies, St. Augustine campus
The Republic of Trinidad and Tobago.
Copyright: delloyd2000© All rights reserved.